Because of the integral blower design, venting is also permitted directly through an outside wall, making it ideal for installations in which no chimney is available, such as converting electrically heated homes, apartments and condominiums. The HVX-70 NG Residential Gas Boiler can also be commonly vented with a conventional gas water heaters into a traditional masonry or Type B chimney. Optional Noncombustible floor pan for use on combustible floors